The biostratigraphic interpretations question the biochronologic significance given hitherto to the genus Offner?a wliicll wRs regarded as a Lower Aptian maxker (Paquier 1905; Masse 1976, 1995) of the Mediterranean regions, a point of view also adopted for the Caribbean (Rojas et al. 1995). Hellce, thel"8 RI'6 two possibilities concerning 'this

geI1US:

— it first appeared in the Middle East during the Late Barremlan RIld Inlglated latBI' GD 1D the Mediterranean (and Caribbean' ?) regions, where it is confined to the Lower Aptian;

— 1'ts Stratigraphic posltloX1 lIi the Medrtell RDBall I'BgioDS, relative 'to the Barr emlan-Aptlan boUI1- dal'y„wRs wiongly calibrated and Deeds fill"tllel; accurate, investigations in order to disprove its exclusive location in the Lower Aptian.

The data obtained here show that ihe assemblage which consists of; Offner?'a rhodan?ca and Offne ria cf.?nterrur?tc considered so far typical of the French and. Iberic regions (Masse 1985) is present in the Arabian peninsula and is therefore to be 1 egarded R po'teQ'tlal coslnopolltlc RssBQiblRge fol the peliIlledltBITRIleaxl I'BgloI1 arid the Middle East (Fig. 13). The Offneria?nterraptc assembla- ge ls Ilot Rt the SR1118 s'tla'tlgI'aplllc level Rs tile Offneria mUrgens?s RSSBIllblRge Rs BIlvlsRged ear- lier (Masse 1992) but older.

It ls RSSU1Xled that IraecaprM,G ls Xnore pllIIll'tlVB than Offn,eric (PhqUIER, 1905) and that Offneria Interrur?ta and Offneria rhodan?'ca (with a predomi- I1M1't I'adlai 0I'galllzR'tloll Rnd lacklIlg tabulae ln tile body CRVlty) Rl'8 illoI'8 pI'llnltlVB than OffnerWI OHLr" gens?s and Offneri,a? tatica (with a rexnarkable deve- lopment of polygonal canals and having tabulae in the body cavity) (Masse 1992). Offnena ni'coll'nae with a relatively small size is considered the most